I know there'* the option of a PicoPSU or so, but I'd like to know if my 94 SSEi has some power lines available to suit this:
http://pinouts.ru/Power/atxpower_pinout.shtml

Not all PicoPSUs cost that little. The very next one, a 90W, goes for $34.95 before shipping. It might be cheaper also to buy a 400W DC to AC converter for $19.99 + 6% tax I found at a gas station and then use a computer power supply I already have. However, there probably is a better (read: cheaper) way to do this.

I need about 10A (or less) on the 12V rail, about 15A on the 5 and 3.3V rails, and 1.5A on the 5V SB (standby) rail. I know my car technically already has 12V power available, but it goes between high 11s to low 12s when off and mid 14s when the alternator is running. I would like to have a cleaner power supply to stay at around 12V with very, very little oscillation.

Are there some of these power lines already available at the "expected" amperages?

Bump! Help!

I assume you're planning on installing a motherboard in your car? You aren't going to find anything suitable that can be directly utilized as a power source. Filtering and regulation are going to be big issues. Don't forget that you also need -5VDC and -12VDC.

Thanks for responding! I was hoping that I could eek out this power without daisy chaining PicoPSU. Yes, I'm going to see about cramming in one or two boards. I've already got most of the parts, so this should be really cool. Since the PicoPSUs are already in so many cars, it shouldn't be a problem to use them as opposed to desktop PC power supplies. If you do find a way, though, let me know. For now, I'll see if I can contact Seasonic and Hipro. That would be cool!

have you spent any time over at MP3car.com? Have you talked to anyone with the PICOPSU or are you going by the ebay ad? Have you researched the actual power requirements of both your Mobo and the strict requirements?

The other poster is correct with the Voltage regulation issues. You need a very clean power supply to not risk damaging the mobo. In a car, even the 12V line will drop to 9-10 and spike to 14V on occasion, so that needs to be regulated. Even using a 600W DC-AC power converter and then a regular power supply will still have this issue and people have had to go add a line filter/regulator to make sure they had the proper voltage all the time.

I'd say give that website a good read, and use a google search to find more information on the subject.

Thanks for the great post! I'm going to use some more voltage regulators. The cheapest good ones I have found so far are the 12V adapters for 16V solar panels. I have not spoken with PicoPSU, but I'm going with way more than the eBay ads out there. I remember reading about the PicoPSUs way back when they came out, and I was really excited. I've spent some time at MP3Car.com, and on other forums, there was some more chat about this. I feel pretty caught up, and now I just have to get all the parts together.



Low battery. brb

I'm still curious how you plan to approach the -5V and -12V issue. Are you planning on building your own negative power supply with discreet components or use something else?

Actually, I had in the back of my mind the possibility of asking that question later on if I needed to. As I'm aware, I could just leave the -5 line blank because it'* not in the new ATX standard. A -12V power line doesn't really need to be too powerful, but at least some power would be nice.

I'm not yet sure about how to explain the horror of what will occur, but in general, for starters, I have a mini ITX motherboard with a processor, memory, GPU, sound, IDE to CF adapter, and no CD drive needed yet. Another motherboard, full ATX with a good video card and such, will come shortly. Pictures coming tomorrow when there'* enough light for my cell phone camera.

I don't want to discourage you, but before you put any more money into this I really think you need to research this more. A required signal is a required signal regardless of current demand. These must be present in order for some circuitry to function. I would hate to see you spend a bunch of money and not get the result you're after

That'* a great idea. The more and more I read about this, the more I'm leaning towards PicoPSU, herein P. The P was made to solve problems similar to mine, so why not use it? The thing about it is that PicoPSUs are weak for what I'd like to do. I'm already looking to cutting back on the hardware by just a bit. I don't want to use anything with sub-85C rated capacitors, and especially not something that has cheap Taiwanese ones.

I'll continue looking around on other forums, but progress has been made here so far. Thanks for the tips, and I'll come back here with more info. If you happen to find a P wannabe that has 10+ A on the 12V rail, please let me know.